Page:The wealth of nations, volume 1.djvu/47

 circulation, in the market, a commodity whose use-value possesses the peculiar property of being a source of value; whose actual consumption, therefore, is itself an embodiment of labor, and, consequently, a creator of value. The possessor of money does find on the market such a special commodity in capacity for labor or labor power." From this, therefore, comes the surplus value. In other words, the surplus value is unpaid labor. This idea Marx develops with great detail, embodying much trenchant criticism of previous economists. In Part IV, of the first volume of "Das Kapital," Marx shows the development of the modern capitalist system historically, beginning at the break-up of the Middle Ages, during which simple individual or family labor obtained; leading up to simple co-operation, this rapidly developing into the manufacture system prevalent during the so-called période manufacturière, which dates, roughly speaking, from the middle of the sixteenth to the end of the eighteenth century; and this mode of production again, toward the close of the last century and the beginning of the present, passing into the "" of modern times, in which all but the simplest forms of direct human labor are superseded by machinery.

The above cannot, of course, give more than a hint on one or two points dealt with, in what is, in its bearing on human life generally, perhaps the most important work of the century. We may here again remind the reader that the preceding introduction does not profess in any way to be a complete history of the science. Such a history is at